ARCA logo

Asociatia Romana pentru Cosmonautica si Aeronautica (ARCA) or Cosmonautics and Aeronautics Romanian Association is a non-governmental organization that promotes aerospace projects as well as other space-related activities. It is based in Ramnicu Valcea, Romania. Image File history File linksMetadata Arca_logo. ... Râmnicu Vâlcea (population: 107,656) is a city in Vâlcea county, Romania. ...

ARCA site

Beginnings

In Sibiu - Romania, in front of Hermann Oberth memorial house, a group of students decided to change the low-level space activities in Romania. ARCA's members started to develop an ambitious high performance rocket engine in 1998. ARCA was registered in 1999. Since then, ARCA became a united team and, despite a small budget in the first years, it succeeded to lead the field in rocket technology in Romania. Image File history File links 85_engine. ... Sibiu (German: Hermannstadt, Hungarian: Nagyszeben) is a city in Transylvania, Romania with a population of 170,000. ... Oberth (in front) with fellow ABMA employees Hermann Julius Oberth (June 25, 1894 - December 28, 1989) was a German physicist and one of the founding fathers of rocketry and astronautics. ...

The first aerospace project started in 1998 was a high performance rocket engine designed to deliver 85,000 kgf. The engine used open cycle and the 4 burning chambers were fed with liquid oxygen and kerosene at the combustion pressure of 70 bars.

The purpose of this project was to develop the abilities and skills needed for future activities by using local technology and materials. Another achievement was the creation of a united and specialized team of rocket engineers.

Early Vehicles

Demonstrator

Demonstrator

This technological demonstrator is at 1:2 scale of that of the X PRIZE vehicle, named Orizont and it is the first rocket designed by ARCA Team. It is an unguided, but self stabilized rocket. On this vehicle and on sub-assembly systems were tested many constructive solutions, especially composite materials fuel tanks. Almost the entire structure is made of composite materials, but also from aluminium aloys. This rocket was created to simulate an almost complete (unmanned) X Prize mission. Demonstrator 1 was also used in public exhibitions in order to attract more funds for ARCA projects. Image File history File links Dem1_vehicle. ... The X prize logo shows a stylised letter X representing a spacecraft trajectory and containing a starfield. ...

The old configuration used a liquid fuel rocket engine, designed to thrust 2,000 kgf during 60 sec. The fuel was: hydrogen peroxide 85% + T1. In the new configuration will use a hybrid engine with hydrogen peroxide 85% as an oxidizer, in combination with polyethylene as fuel.

Demonstrator 2

Demonstrator 2

he technological demonstrator "2" is at 1:2.5 scale of that of the X PRIZE vehicle, named Orizont. ARCA started the work to this rocket in May 2003. The entire structure is made of composite materials. For this vehicle was created a whole launch complex, including the launch pad, the fuel transfer facility, etc. For this vehicle was proposed two propulsion configurations: monopropellant and hybrid. Image File history File links Dem2_vehicle. ...

Demonstrator 2 was the starting point for the development of the successful Demonstrator 2B rocket. You can see more large pictures with this rocket here The first public display of this vehicle took place in Dragasani, on September 27, 2003. Drăgăşani is a town in the Vâlcea county, Romania, near the right bank of the Olt river, and on the railway between Caracal and Râmnicu Vâlcea. ...

Demonstrator 2B

Demonstrator 2B

Demonstrator 2B is a modified version of Demonstrator 2, equipped with the world`s first reusable rocket engine made of composite materials. The main objective of this rocket was to test in flight the engine and the vehicle-launch pad interaction in order to gather more data for the Orizont vehicle construction. For the Demonstrator 2B launch was used the Demonstrator 2 launch pad which was modified (the length was increased to 18.2 m) and also the command panel and fuel transfer facility previously developed at ARCA. Image File history File links Dem2b_vehicle. ...

This rocket was the end of subscale systems tests at ARCA and the beginning of the Orizont vehicle`s final phase of construction.

The Demonstrator 2B rocket was successfully launched on September 9, 2004. The measurements indicated that the launch parameters were: 1000 m altitude, 630 km/h, 2100 m range.

Orizont

The construction of ORIZONT begun in mid-2004. At that time, ARCA was more concerned on the launch of Demonstrator 2B from Cape Midia and most of the members declined the involvement in the ambitious ORIZONT project. However, a small group started the design and the construction of the new vehicle. The first element was the mold for the presurised compartment of the spacecraft. The mold and the whole structure of the cabin were finished in february 2005.

The work itself was done in a very small workshop and it was obvious that the team needed a much larger space for the equipments and hardware.

At the beginning of June one of the major sponsors of ARCA offered an assembly facility of 1500m2. Here, they began assembling the ORIZONT vehicle.

The launch

The air-launch solutions are flexible due to the variable geometry of the wings and the solutions that were selected for the propulsion system. The launch can be executed, depending of the carrier availability, from helicopter or airplane. In every situation the launch will be made with the wings at near 0 degrees sweep angle because it is necessary that the wing to generate the highest possible lift. In the case of helicopter launch, the ORIZONT vehicle will be lift to an altitude of around 2.000-2.500 m. At this altitude, the vehicle will be released and it will gravitationally accelerate to the requested speed of about 210 km/h, necessary for the stable flight. In the case of the air launch, the ORIZONT vehicle will be transported to altitudes around 11.000 m, attached to the carrier at the top or at the bottom. Due to safety reasons, it is better to attach the vehicle at the bottom of the carrier. The launch from the helicopter is easier to implement from the logistical and technical point of view, but increases the stress of the cosmonaut because of the necessity to fly the ship in the atmosphere for a longer period of time.

The autonomous atmospheric flight

After the carrier release, the ORIZONT vehicle will start the air-breathing engine and will start to climb with the wings completely open to an altitude of around 17.000 m with a speed range of about 400-700 km/h. The maximum acceleration for this stage of the flight will be no higher than +4,6/-1,6 G

Rocket engine start preparations

Immediately after the vehicle will reach the desired altitude, the air-breathing engine will be detached. This action is shortly followed by the modification of the wing sweep angle to a minimum value. The lift and drag will decrease significantly.

Rocket engine vertical flight

The rocket engine will be started when ORIZONT will have 45 degrees angle of attitude which can be obtained from the stabilizers. Immediately after the start the vehicle will begin to accelerate rapidly, the aerodynamic surfaces putting the vehicle to a near vertical trajectory. This trajectory will be kept for the entire time of the rocket engine run.

The inertial vertical flight and the reentry preparations

After the rocket engine shut-down the ship will continue to climb inertial in vertical position, in this time frame, the pilot will start the reconfiguration of the whole ship for the reentry mode: the wing sweep angle will be changed to a negative position and the stabilizers will change their position with 180. The low atmospheric density from those altitudes will not allow the pilot to control the attitude of the ship from the aerodynamic surfaces and the ship will be controlled with the reaction control system (RCS).

The flight at maximum altitude

At the maximum altitude of 100 km, the ship will have the lowest speed from the entire flight sequence. The pilot will continue to control the ship with the RCS.

The reentry

After reaching the 100 km altitude, the vehicle will start the descent. For less then half the distance, the pilot will experience the effects of imponderability. The ship must be kept with the RCS in vertical position with the nose up. This process does not request an intense solicitation from the pilot since in some degree, big attitude errors are even allowed. When the ship will encounter the first dense atmospheric layers the use of the RCS is not necessary, the ship, due to the unique variable geometry system, will become auto stabilized aerodynamically and inertial. The maximum deceleration at reentry will reach -6,2 G for only 4 sec.

The recovery

Even though the variable geometry of the vehicle would allow a landing procedure on a runway, ARCA decided that the parachuted recovery system is safer from the following considerations:

- in the case of a trajectory error during the rocket engine powered flight, the vehicle could be deviated far away from the runaway

- the necessity of a runaway presence limits the flight corridor definition possibilities.

- the stress for the pilot is lowered because it suppressed the necessity of a runaway landing procedure.

- it offers the possibility to abort the mission in almost every sequence of the flight and to bring the ship safely at the ground.

The deceleration parachute will be extracted at a height of about 6.000 m and this operation is shortly followed by the main parachute extraction at 4000 m. The whole parachute system is placed in the front of the ship, at the bottom of the cabin. The landing in the sea will take place at a speed no higher than 7m/s. The stress over the pilot, from the rocket engine shut-down to the landing moment is reduced significantly.

Other projects

STRACAAT

In November 2005 ARCA succeeded to win a contract with the Research Ministry/Romanian Space Agency for the development of a rocket system with military applications. The contract was awarded for a period of 12 months.

The system is called STRACAAT and it will be used to simulate an airborne target at high speeds/low altitudes such attack airplanes/helicopters.

The rocket will be 6m long at a launch weight of 400kg. The evolution parameters will be: altitude: 10 km; range: 20 km, max. speed 300 m/s.

Stabilo

ARCA designed and is developing a new sub-orbital vehicle called: STABILO. The name was proposed by ARCA’s engineers because of vehicle’s unique performance to be stable at speeds between 0-1100m/s without using stabilizing systems or aerodynamic surfaces.

The composite materials airframe was 80% completed. The fuel tank tests started in January and the engine will be tested in March. The first automated flight of this low cost vehicle, at an altitude above 100 km will be made in less than 12 month.

For this vehicle ARCA will use the technology developed during the Demonstrator 2B successful program, including the composite materials reusable rocket engine.